An integrated physical model of the Three Gorges Project and the downstream approach channel at a scale of 1:80 was used to simulate water level fluctuation in the approach channel of the ship lift under experimental conditions,ie.flood discharge,peaking,and ship lock emptying,and superimposed conditions of the three.The results indicated that the water level fluctuated in downstream approach channel of the Three Gorges Project because of the combination of long wave caused by the flow difference between the two dams and the channel and the fluctuation in the approach channel.Under condition of a 100-year recurrence flood discharge,the hourly variation of water level for downstream lock head of the ship lift was 061 m/h.The hourly variation of water level for downstream lock head of the ship lift was less than 042 m/h with one time flood discharge adjustment of more than 2 000 m3/s.Under conditions of peaking,the first wave amplitude of fluctuation in downstream approach channel of the ship lift increased with the increase of flow amplitude and variable rate,while the variable rate depended on the flow amplitude and the net flow between the two dams.When the two lines of ship lock empty at the same time,the water level fluctuation for downstream lock head of the ship lift had no significant impact on running of the ship lift with a maximum hourly variation of 018 m/h.